WASHINGTON — The Supreme Court on Saturday allowed Texas to use its strict voter identification law in the November election. The court’s order, issued just after 5 a.m., was unsigned and contained no reasoning.

Justice Ruth Bader Ginsburg issued a six-page dissent saying the court’s action “risks denying the right to vote to hundreds of thousands of eligible voters.”

Justices Sonia Sotomayor and Elena Kagan joined the dissent.

The court’s order was an interim move addressing emergency applications filed Wednesday, and a trial judge’s ruling striking down the law will still be appealed. But the Supreme Court’s action set the ground rules in Texas for the current election. Early voting there starts Monday, which helps explain the court’s rush to issue the order as soon as Justice Ginsburg had finished her dissent.

The law, enacted in 2011, requires voters seeking to cast their ballots at the polls to present photo identification like a Texas driver’s or gun license, a military ID or a passport.

Those requirements, Justice Ginsburg wrote, “may prevent more than 600,000 registered Texas voters (about 4.5 percent of all registered voters) from voting in person for lack of compliant identification.”

“A sharply disproportionate percentage of those voters are African-American or Hispanic,” she added, adding that “racial discrimination in elections in Texas is no mere historical artifact.”

Texas officials quarreled with Justice Ginsburg’s math, which was drawn from evidence presented to a trial court. In their brief urging the justices to allow the election to proceed under the 2011 law, they said that trying to determine the number of people the law would deter from voting was a fool’s errand and called the estimate of 600,000 disenfranchised voters preposterous.

Justice Ginsburg also said the law “replaced the previously existing voter identification requirements with the strictest regime in the country.”

She noted that Texas would not accept several forms of ID that Wisconsin did, including “a photo ID from an in-state four-year college and one from a federally recognized Indian tribe.” The Supreme Court on Oct. 9 refused to let Wisconsin use its voter ID law in the current election.

Texans who lack a required form of identification cannot easily obtain it, Justice Ginsburg wrote. “More than 400,000 eligible voters face round-trip travel times of three hours or more to the nearest” government office issuing IDs, she wrote, and they must generally present a certified birth certificate.

Birth certificates ordinarily cost $22. The state offers ones costing $2 to $3 for election purposes, Justice Ginsburg wrote, but it has not publicized that option on the relevant website or on forms for requesting birth certificates.

“Even at $2, the toll is at odds with this court’s precedent,” she wrote, citing a 1966 decision striking down Virginia’s poll tax.

The Texas law was at first blocked under Section 5 of the federal Voting Rights Act, which required some states and localities with a history of discrimination to obtain federal permission before changing voting procedure. After the Supreme Court in 2013 effectively struck down Section 5 in Shelby County v. Holder, an Alabama case, Texas officials announced that they would start enforcing the ID law.

The law has been challenged by an array of individuals, civil rights groups and the Obama administration.

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A voter showing photo identification in Austin, Tex., in February. A federal judge had blocked enforcement of a 2011 law.CreditEric Gay/Associated Press

Attorney General Eric H. Holder Jr. released a statement Saturday criticizing the outcome.

“It is a major step backward to let stand a law that a federal court, after a lengthy trial, has determined was designed to discriminate,” he said. “It is true we are close to an election, but the outcome here that would be least confusing to voters is the one that allowed the most people to vote lawfully.”

After a two-week trial in September, Judge Nelva Gonzales Ramos of Federal District Court in Corpus Christi struck down the law on Oct. 9 in a 147-page opinion. She said it had been adopted “with an unconstitutional discriminatory purpose,” created “an unconstitutional burden on the right to vote” and amounted to a poll tax.

Two days later, Judge Ramos entered an injunction blocking the law in the current election. The question for the justices was what to do about that injunction while appeals proceed.

Greg Abbott, the state attorney general and the Republican candidate for governor, told the Supreme Court that Judge Ramos had acted too closely to the election and had “unsettled a status quo that had prevailed for 15 months and governed numerous elections without a hitch.”

He accused his adversaries of litigation gamesmanship in not seeking a preliminary injunction while the case was moving forward in the trial court. A ruling on such an interim injunction, he said, would have allowed an orderly appeal.

On Tuesday, a three-judge panel of the United States Court of Appeals for the Fifth Circuit, in New Orleans, stayed Judge Ramos’s injunction. It said a change in voting rules so close to an election would cause confusion among voters and poll workers.

The law has been used in several statewide elections since the 2013 decision but never in a federal general election.

Texas has required some form of identification to vote at the polls since 2003. In the decade after, before the new law imposed even stricter requirements, some 20 million votes were cast, Solicitor General Donald B. Verrilli Jr. told the justices, while “only two cases of in-person voter-impersonation fraud were prosecuted to conviction.”

A brief filed by the Texas State Conference of N.A.A.C.P. Branches and other groups said confusion at the polls was unlikely under Judge Ramos’s injunction. “Expanding the list of acceptable IDs will not disenfranchise any voter,” the brief said, “since the forms of ID acceptable under the old voter ID system include all forms of photo ID specified by” the 2011 law.

Justice Ginsburg agreed, adding that Judge Ramos had found “the state’s efforts to familiarize the public and poll workers regarding the new identification requirements” to be “ ‘woefully lacking’ and ‘grossly’ underfunded.”

“In short,” Justice Ginsburg wrote, “any voter confusion or lack of public confidence in Texas’ electoral processes is in this case largely attributable to the state itself.”

A spokeswoman for the Texas attorney general’s office said the state “will continue to defend the voter ID law and remains confident that the District Court’s misguided ruling will be overturned on the merits.” She added that “the U.S. Supreme Court has already ruled that voter ID laws are a legal and sensible way to protect the integrity of elections.”

The order was the fourth time the Supreme Court has interceded in the coming election in the last three weeks. The moves were in one sense hard to reconcile.

The court allowed Ohio to cut back on early voting and let North Carolina bar same-day registration and the counting of votes cast in the wrong precinct. But the court also stopped Wisconsin from requiring voters there to provide photo ID.

The theme that did seem to run through the orders was a reluctance to disturb the status quo immediately before an election.

Justice Ginsburg said the Supreme Court’s order Saturday morning was different from the ones issued concerning Ohio and North Carolina. “Neither application involved, as this case does,” she wrote, “a permanent injunction following a full trial and resting on an extensive record from which the District Court found ballot-access discrimination by the state.”

A version of this article appears in print on , on Page A19 of the New York edition with the headline: Supreme Court Allows Texas to Use Strict Voter ID Law in Coming Election. Order Reprints | Today’s Paper | Subscribe